Centreboard casing constructions for sailing boats

ABSTRACT

A device for extending the vertical height of a centre-board slot in a sailing boat hull comprising a vertically extending casing the lower part of which has a horizontal extending aperture adapted for alignment with the upper end of the slot in the hull, and a resilient gasket for connecting and sealing the casing to the hull.

United States Patent [1 1 Thorpe [451 Nov. 26, 1974 CENTREBOARD CASINGCONSTRUCTIONS FOR SAILING BOATS [75] Inventor: David C. Thorpe, London,England [73] Assignee: Richmond Marine Limited,

Twickenham, Middlesex, England [22] Filed: Nov. 13, 1972 [21] Appl. No.:305,900

[30] Foreign Application Priority Data Jan. 3, 1972 [52] US. Cl.114/138, 114/132 [51] Int. Cl B63b 41/00 [58] Field of Search114/127-141 [56] References Cited UNITED STATES PATENTS Rice 114/128Great Britain 00075/72 2,466,006 4/1949 Danko 114/138 3,291,091 12/1966Koenig 114/132 FOREIGN PATENTS OR APPLICATIONS 878,936 10/1961 GreatBritain.. 114/132 1,005,758 9/1965 Great Britain 114/127 PrimaryExaminer-Trygve M. Blix Assistant Examiner-Stuart M. Goldstein Attorney,Agent, or FirmBaldwin, Wight & Brown 5 7 ABSTRACT A device for extendingthe vertical height of a centreboard slot in a sailing boat hullcomprising a vertically extending casing the lower part of which has ahorizontal extending aperture adapted for alignment with the upper endof the slot in the hull, and a resilient gasket for connecting andsealing the casing to the hull.

18 Claims, 4 Drawing Figures PATENTE L3V26l974 SHEEI 2 OF 2 CENTREBOARDCASING CONSTRUCTIONS FOR SAILING BOATS This invention relates tocentre-board casing constructions for sailingboats.

The term centre-board will be used throughout the specification toinclude not only centreboards which can be lowered from a boat hull byrotating about a pivot but also dagger boards which are merely movedvertically up and down and any other kind of device which is utilised toincrease the wetted area of a sailing boat hull and which projects fromthe hull through a slot therein. Such devices are sometimes referred toas drop keels or even centre plates, the later usually referring todevices made from metal and such boards, plates or keels may be arrangedon the centre line of the hull or to one side thereof. For example, itis known to provide two centre-boards one towards each side of the hulland catamarans and asymmetric hulls sometimes have asymmetricarrangements.

In any case, it is always necessary to provide a slot in the hull whichextends upwardly to a point which is higher than the water line of thehull concerned to pre-v vent water entering the boat unless the top ofthe slot is sealed. Sealing the top of the slot can however presentdifficulties especially in the case of a pivoted rotating centre-boardbecause it means that the top of the slot must be high enough toaccommodate the full width of the board when it is retracted and this,in some circumstances can be higher than the gunwhale of the boat. Inthese circumstances therefore it is necessary for the top of the slot tobe open but for it to be high enough above the water line to prevent theentry of water. Similarly in the case of a dagger board which is merelypushed up and down through the slot it is necessary to be able to handlethe upper end of the board which requires it to project from the upperend of the slot.

From the above it will be appreciated that the housing in which the slotis provided must, of necessity, occupy a considerable amount of spacevertically in an open hull, that is, a hull which is not decked over.The fact that the housing extends into the hull effectively preventssuch open hulls being stacked within each other for transport andstorage purposes. In certain circumstances when the hulls are deep atcertain amount of stacking can be achieved but in relatively shallowhulls with centre-board housings of the necessary height it is notpossible and the present invention is intended to provide a device and aconstruction of a sailing boat which will enable such stacking to takeplace.

According to the present invention a device for extending the verticalheight of a centre-board slot in a sailing boat hull comprises avertically extending casing the lower part of which has a horizontallyextending aperture adapted for alignment with the upper end of the slotin the hull. and means for connecting and sealing the casing to thehull.

Thus. the hull of the boat can be made without a centre-board housing ofconventional kind, or with one of only a short vertical height so thatthe hulls can be stacked one within the other. When it is necessary touse the boat however or it has been delivered from the manufacturer. itis merely necessary to fasten in place the device set forth to completea centre-board slot which is deep enough for operational use.

in one preferred embodiment the aperture in the casing has a horizontalwidth and a length which are substantially the same as the upper end ofthe slot in the hull but in another construction the width of theaperture may be greater than the width of the upper end of the slotinthe hull thus virtually forming a hollow chamber over the slot.

As mentioned above the slot in the hull may be merely in the bottom ofthe hull or it may be continued upwardly by a short centre-board housingwhich is integral with the hull.

If the device is for use with a dagger board or deep centre board thenthe aperture in the casing may be arranged to also open verticallyupwards and the upward part of the aperture will thus preferably besubstantially the same as the width of the upper part of the slot in thehull.

In a convenient construction the lower part of the casing is providedwith a horizontally projecting flange adapted for connection to thehull, that is the floor of the craft or the small centre-board housingif one is provided.

Preferably each side of thecasing spacedapart across the width of theaperture is provided'with a horizontally extending toe rail under whichthe crew of the craft can hook their tows when sitting out if the craftis a sailing dinghy.

Each toe rail may be arranged to project downwardly from a horizontallyextending flange provided on the casing and this flange can beanextension of the flange which is adapted for connection to the hullwhen the device is intended for use with a short centre-board housing.

Conveniently the casing can be made from a plastics material such asglass fibre.

If the casing is intended for connection to the floor of the hull thenmeans may be provided for pivoting a rotating centre-board within it.

The invention also includes a sailing boat having a centre-board slot inits hull and provided with a device for extending its vertical height asset forth above.

The slot may'be formed in the sailing boat in a vertically extendingcentre-board housing integral and projecting upwardly from the bottom ofthe boat and .to which the casing is connected.

Preferably the centre-board housing has a sealing surface whichsurrounds the slot and to which the casing is connected and a resilientgasket may be provided between the casing and the sealing surface on thehousing.

ln constructions in which the width of the aperture in the lower end ofthe casing is wider than the upper end of the slot in the centre-boardhousing a resilientgasket may be provided which extends inwardly from.the sealing surface to project over the edge portions of the slot.

In one preferred construction the vertically extending sides of thecentre-board casing are hollow and are closed at the upper ends by thesealing surface.

A construction of this type can conveniently be achieved by making thesailingboat from a plastics material such as fibre glass.

Also included in the invention is a kit of parts'for assembling thesailing boat including a device as set forth above and a hull adapted toreceive it. Such a kit of parts enables the manufacturer to stack theboats for transport or storage purposes and the device in the form of acasing is only assembled into the hull when the craft is delivered,

The invention may be performed in many ways and some embodiments willnow be described by way of example and with reference to theaccompanying drawings in which:

FIG. 1 is a cross-sectional side view of a sailing boat embodying theinvention;

FIG. 2 is an enlarged view of part of the centre-board housing of theboat shown in FIG. 1;

FIG. 3 is a part sectional side elevation of an altemative construction;

FIG. 4 is a cross-sectional side view of a boat including anotheralternative construction. 7

In the boat according to the invention shown in FIGS. 1 and 2 the hull lis formed from two glass fibre mouldings, the inner moulding 2 nestingwithin the outer moulding 3. A slot 4 is provided in the hull on thecentre line and extends upwardly through a housing 5 to a point where itis about 1 inch higher than the water line of the hull when floating,this water line being indicated by line 6 in FIG. 1. The construction ofthe hull is such that the vertically extending walls 7 of the slot 4 areformed by the outer moulding 3, the upper end of these walls 7 having anoutwardly projecting flange 8 which extends all around the slot 4 andwhich is sealed to a co-operating flange 9 which extends inwardly fromwalls 10 which are provided on the inner mould 2 and which thus act asthe outer surfaces of the centre-board housing and the walls of thehousing as such therefore are hollow. A chock 11 is secured into thecorners between the flange 9 and walls 10 to provide rigidity and thetwo moulds 2 and 3 are secured together where they engage one another bya suitable adhesive.

The vertical height of the short centre-board housing which is thusproduced is low enough to enable a num-' ber of such hulls to be stackedwithin each other thus considerably reducing the amount of spacerequired for storage or transport.

With this short casing the boat would be unsuitable for sailingbecause-although the centre-board'ho'using is above the water line anyexcessive loading or a rough sea would tend to cause water to enter thehull through the top of the slot and in order to obviate this and raisethe effective height of the centre-board slot 4 a device in the form ofa casing 12 is provided. This is made from glass fibre in a similarmanner to the hull and comprises vertically extending walls 13 the upperends of which project inwardly to form flanges 14 which terminate in aslot 15. The lower end of the casing has an aperture 16 the width ofwhich transverse to the centre line of the hull is greater than thewidth of the upper end of the slot 4 but the slot 15 is of substantiallythe same width of the slot 4 and the length of the slot 15 along thelongitudal axis of the boat is also the same as the-slot 4. The slot 15thus enables the aperture 16 in the casing to open vertically upwards.

The lower part of the casing 12 is provided with a horizontallyprojecting flange 17 provided with holes (not shown) through whichscrews are passed to secure the flange to the flanges 8 and 9 of thehousing the screws being accommodated in the chock 11. In order toprovide effective sealing agasket 18 made fromfoam neoprene is providedbetween the flange l7 and the flange 9 and the upper surface of theflange 9 thus acts as a sealing surface on the housing, this surfacesurrounding the slot 4.

Each side of the casing spaced apart across the width of the aperture 16is provided with a horizontally extending toe rail 19 which projectsdownwardly from a horizontally extending flange 20. This toe rail is forthe use of the crew of the boat when they desire to sit out so that theycan hook their toes beneath the toe rail 19 to support themselves.

In order to stiffen the toe rail transversely extending webs 21 areprovided in the moulding.

From the above description it will be appreciated that a manufacturercan construct boats as set forth above and despatch them or store themnested or stacked one within the other. On arrival or when re- .quiredfor use the casing 12 is screwed into position and the craft can besafely used, a dagger board shown in broken lines in FIG. 1 is locatedin the slots 4 and 15 in known fashion and it can of course becompletely removed if desired, without water entering the craft.

It will be seen from FIG. 2 that the gasket 18 is continued over theedge of the slot 4 and thus acts as a seal around the dagger board tofurther prevent water splashing upwardly through the slot 15 or into theinterior of the casing 12.

In FIG. 3 a construction is shown which can be used for a rotatingcentre-board. In this construction similar reference numerals are usedfor similar parts. The hull l is provided with a centre-board slot 4 ofvery short vertical height but of much longer length than that shown inFIGS. 1 and 2 to accommodate a rotating centre-board 25 which is carriedon a pin 26 which passes through suitable holes in walls of thecentre-board housing 27. In this construction the height of the housingis considerably below the water line of the craft so a device accordingto the invention is provided to raise the height of the slot 4. Thisdevice comprises a casing 28 shaped to accommodate the plate and ofsimilar transverse width to the slot 4 and having flanges 29 around itslower periphery which can be connected by nuts and bolts 30 to flange 31which extends around the upper periphery of the housing 27. A sealinggasket 32 is provided between the flanges 29 and 31 to seal the joint.

In this construction the upper end of the slot 33 provided in the casing28 and within which the board moves is closed apart from a smallaperture 32 through which passes a control line or lines 34, these linesbeing used to raise or lower the centre-board.

Once again a construction is provided which enables boats to be nestedone within the other when the casing 28 and centre-board 25 are not inposition.

In an alternative construction (not shown) the arrangement is verysimilar to that shown in H6. 3 but the short housing27 is omitted,merely a slot being provided in the bottom of the hull. The sides of thecasing 28 are extended lower so that the flange 29 can be bolteddirectly to the bottom of the hull land the pivot pin 26 is carried inthe walls of the casing 28. With this construction the centre-board canbe pre-mounted in the casing 28 and the whole assembly then secured tothe bottom of the boat. When the casing 28 is removed,

together with the centre-board the bottom of the boat is completelyclear.

In FIG. 3 the centre-board is shown in broken lines in its loweredposition.

- In the construction shown in FIG. 4 the various parts of the boat areindicated by similar reference numerals to those used in FIGS. 1 and 2and the hull construction is similar including the hollow sides to thecentre-board casing. In this arrangement however a pivoting centreboard41 is used. A casing 42 extends the vertical height of the centre-boardslot 43 in a similar manner to that described with reference to FIGS. 1and 2 and the upper end of the casing 42 is again provided with aslot-like opening 44 through which the centre-board 41 projects when itis in its raised position as shown in full lines in FIG. 4. Thecentre-board is located on a pin 45 carried between a pair of hangers 46each hanger 46 being in the form of an inverted L-shaped bracket. Eachof the horizontally extending arms of the brackets rest on the flanges 8and 9 and are secured by nuts and bolts so that the vertically extendingarm of the bracket projects down the side of the wall 7 of the slot 43.The pin 45 is carried between these hangers 46 and thus 10- cates thecentreboard in the housing so that it can pivot about the pin in knownfashion.

This is a particularly useful construction as it enables the weight ofthe centre-board on its pin 45 to be more evenly distributed onto theglass-fibre hull and a plate of maximum chord can be used without havingto provide a very high casing. It will be appreciated that the height ofthe casing 42 is of course above the water line level of the hull whenit is afloat.

I claim:

1. A new article of manufacture comprising a device for extending thevertical height of a centre-board slot in a sailing boat hull of thetype including a hull bottom having a centre-board slot therethrough andthe slot extending above the hull bottom through a centre-board housingprojecting upwardly from the hull bottom, said device including avertically extending casing the lower part of which has a horizontallyextending aperture adapted for alignment with an upper end of the slotin the centre-board housing, said aperture being of a horizontal lengthto have received therein the full horizontal dimension of thecentre-board for which said device is intended, and connecting means forconnecting and sealing the lower part of the casing to the upper part ofthe centre-board housing.

2. A device as claimed in claim 1 in which the aperture has a horizontalwidth and length which are substantially the same as the upper end ofthe slot in the centre-board housing.

3. A device as claimed in claim 1 in which the width of the aperture isgreater than the width of the upper end of the slot in the centre-boardhousing.

4. A device as claimed in claim 1 in which the aperture in the casingalso opens vertically upwards.

5. A device as claimed in claim 4 in which the width of the upper partof the aperture is substantially the same as the width of the upper partof the slot in the centre-board housing.

6. A device as claimed in claim 1 in which the connecting means includesthe lower part of the casing being provided with a horizontallyprojecting flange for connection to the centre-board housing.

7. A device as claimed in claim 1 in which each side of the casingspaced apart across the width of the aperture is provided with ahorizontally extending toe rail.

8. A device as claimed in claim 7 in which each toe 'rail projectsdownwardly from a horizontally extending flange provided on the casing.

9. A device as claimed in claim 1 in which the casing is made from aplastics material.

10. A device as claimed in claim 8 in which the casing is made fromglass fibre.

11. A device as claimed in claim 1 in which the casing is provided withmeans for pivoting a rotating centreboard.

12. A sailing boat including a hull having a bottom and a centre-boardhousing projecting upwardly from said bottom in sealed relation thereto,and a centre board slot in said hull, said slot extending through saidbottom of said hull and vertically upwardly therefrom through saidcentre-board housing, and said hull being provided with a deviceextending the vertical height of the centre-board slot, said deviceincluding a vertically extending casing the lower part of which has ahorizontally extending aperture in alignment with the upper end of theslot in the hull, and connecting means on the lower part of the casingconnecting and sealing the casing to the hull above said hull bottom inupwardly slot extending relation to said centre-board housing.

13. A sailing boat as claimed in claim 12 in which the centre-boardhousing has a sealing surface which surrounds the slot at the upper endthereof and to which the casing is connected.

14. A sailing boat as claimed in claim 13 in which said connecting meansincludes a resilient gasket is provided between the casing and thesealing surface on the housing.

15. A sailing boat as claimed in claim 14 in which the width of theaperture in the lower end of the casing is wider than the upper end ofthe slot in the centre-board housing and the resilient gasket extendsinwardly from the sealing surface to project over the edge portions ofthe slot.

16. A sailing boat as claimed in claim 13 in which the verticallyextending sides of the centre-board housing are hollow and are closed attheir upper ends by the sealing surface.

17. A sailing boat as claimed in claim 12 made from a plastics material.

18. A sailing boat as claimed in claim 12 in which the casing has meansdepending therefrom into said slot for pivoting a rotating centre-board.

1. A new article of manufacture comprising a device for extending thevertical height of a centre-board slot in a sailing boat hull of thetype including a hull bottom having a centreboard slot therethrough andthe slot extending above the hull bottom through a centre-board housingprojecting upwardly from the hull bottom, said device including avertically extending casing the lower part of which has a horizontallyextending aperture adapted for alignment with an upper end of the slotin the centre-board housing, said aperture being of a horizontal lengthto have received therein the full horizontal dimension of thecentre-board for which said device is intended, and connecting means forconnecting and sealing the lower part of the casing to the upper part ofthe centre-board housing.
 2. A device as claimed in claim 1 in which theaperture has a horizontal width and length which are substantially thesame as the upper end of the slot in the centre-board housing.
 3. Adevice as claimed in claim 1 in which the width of the aperture isgreater than the width of the upper end of the slot in the centre-boardhousing.
 4. A device as claimed in claim 1 in which the aperture in thecasing also opens vertically upwards.
 5. A device as claimed in claim 4in which the width of the upper part of the aperture is substantiallythe same as the width of the upper part of the slot in the centre-boardhousing.
 6. A device as claimed in claim 1 in which the connecting meansincludes the lower part of the casing being provided with a horizontallyprojecting flange for connection to the centre-board housing.
 7. Adevice as claimed in claim 1 in which each side of the casing spacedapart across the width of the aperture is provided with a horizontallyextending toe rail.
 8. A device as claimed in claim 7 in which each toerail projects downwardly from a horizontally extending flange providedon the casing.
 9. A device as claimed in claim 1 in which the casing ismade from a plastics material.
 10. A device as claimed in claim 8 inwhich the casing is made from glass fibre.
 11. A device as claimed inclaim 1 in which the casing is provided with means for pivoting arotating centre-board.
 12. A sailing boat including a hull having abottom and a centre-board housing projecting upwardly from said bottomin sealed relation thereto, and a centre-board slot in said hull, saidslot extending through said bottom of said hull and vertically upwardlytherefrom through said centre-board housing, and said hull beingprovided with a device extending the vertical height of the centre-boardslot, said device including a vertically extending casing the lower partof which has a horizontally extending aperture in alignment with theupper end of the slot in the hull, and connecting means on the lowerpart of the casing connecting and sealing the casing to the hull abovesaid hull bottom in upwardly slot extending relation to saidcentre-board housing.
 13. A sailing boat as claimed in claim 12 in whichthe centre-board housing has a sealing surface which surrounds the slotat the upper end thereof and to which the casing is connected.
 14. Asailing boat as claimed in claim 13 in which said connecting meansincludes a resilient gasket is provided between the casing and thesealing surface on the housing.
 15. A sailing boat as claimed in claim14 in which the width of the aperture in the lower end of the casing iswider than the upper end of the slot in the centre-board housing and theresilient gasket extends inwardly from the sealing surface to projectover the edge portions of the slot.
 16. A sailing boat as claimed inclaim 13 in which the vertically extending sides of the centre-boardhousing are hollow and are closed at their upper ends by the sealingsurface.
 17. A sailing boat as claimed in claim 12 made from a plasticsmaterial.
 18. A sailing boat as claimed in claim 12 in which the casinghas means depending therefrom into said slot for pivoting a rotatingcentre-board.